Cisco 350-401 Implementing Cisco Enterprise Network Core Technologies (ENCOR) Exam Dumps and Practice Test Questions Set 3 Q41-60

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Question 41:

Which protocol is used to securely exchange routing updates between OSPFv3 neighbors in an IPv6 network?

A) IPsec
B) MD5 authentication
C) GRE
D) SSL

Answer:

A) IPsec

Explanation:

Open Shortest Path First version 3 (OSPFv3) is the IPv6-specific version of OSPF, and unlike OSPFv2, it does not include built-in authentication for securing routing updates. In OSPFv2, authentication options such as plain text and MD5 were available to verify routing information between peers. OSPFv3, however, was redesigned to separate the protocol operation from addressing, delegating security to the IPv6 protocol itself. To secure routing updates in OSPFv3, IPsec is used to provide authentication, integrity, and confidentiality.

IPsec (Internet Protocol Security) is a suite of protocols that provides cryptographic services for IP traffic. For OSPFv3, IPsec is typically configured in transport mode between directly connected routers. It ensures that OSPFv3 packets are authenticated and cannot be altered during transit. IPsec supports multiple authentication methods, such as pre-shared keys and digital certificates, and encrypts the OSPFv3 messages using secure encryption algorithms. This combination ensures both message integrity and confidentiality, protecting the routing infrastructure from spoofing, tampering, and eavesdropping attacks.

The process begins with configuring IPsec Security Associations (SAs) between OSPFv3 neighbors. Routers exchange keying material to authenticate each other, typically using the Internet Key Exchange version 2 (IKEv2) protocol. Once the SAs are established, OSPFv3 messages are encapsulated within IPsec headers before transmission. The receiving router verifies the IPsec headers, authenticates the sender, and decrypts the message to ensure the integrity of the routing information.

Other options listed do not provide the same level of security for OSPFv3. MD5 authentication was used in OSPFv2 but is not natively supported in OSPFv3 because security responsibilities were moved to IPsec. GRE (Generic Routing Encapsulation) provides tunneling but no authentication or encryption. SSL is designed primarily for securing application-layer traffic, such as HTTPS, and is not applicable to routing protocols.

Securing OSPFv3 with IPsec is crucial in enterprise networks and service provider environments where IPv6 routing occurs over untrusted networks. Without IPsec, malicious actors could inject false routing updates, potentially causing network outages or misrouting traffic. IPsec also complements other security mechanisms, such as firewall policies and network segmentation, providing a layered security approach that ensures both the control plane (routing) and data plane are protected.

In conclusion, IPsec is the correct method for securing OSPFv3 routing updates in IPv6 networks. It provides authentication, integrity, and confidentiality, ensuring that routing information cannot be tampered with or intercepted, making option A correct.

Question 42:

Which WAN technology provides a virtual point-to-point connection using MPLS and supports multiple tenants in an enterprise network?

A) Frame Relay
B) MPLS VPN
C) Metro Ethernet
D) DSL

Answer:

B) MPLS VPN

Explanation:

MPLS (Multiprotocol Label Switching) VPNs are a widely deployed WAN technology in enterprise networks, enabling secure, scalable, and efficient connectivity between geographically dispersed sites. MPLS VPNs use the label-switching capabilities of MPLS to create virtual point-to-point or point-to-multipoint connections over a shared service provider infrastructure while maintaining separation for multiple tenants. This allows enterprises to connect branch offices, data centers, and cloud services with guaranteed isolation and predictable performance.

In an MPLS VPN, service providers create virtual routing and forwarding (VRF) instances for each customer. Each VRF maintains its own routing table, enabling complete separation between customers or different business units within the same enterprise. MPLS labels are used to forward packets along predefined paths without the need for examining the IP header at each hop, improving forwarding efficiency and scalability. This label-based forwarding allows for traffic engineering and prioritization, ensuring that critical applications receive the appropriate quality of service (QoS).

MPLS VPNs can be categorized into Layer 2 VPNs (e.g., VPLS) and Layer 3 VPNs. Layer 2 VPNs provide Ethernet-like connectivity over the MPLS backbone, enabling extension of Layer 2 segments across sites. Layer 3 VPNs, which are more common, operate at the IP layer, with the provider maintaining the routing separation via VRFs. This approach supports overlapping IP address spaces, multi-tenant environments, and centralized policy management.

Other WAN technologies have limitations compared to MPLS VPNs. Frame Relay is largely legacy, offering fixed point-to-point circuits with limited scalability. Metro Ethernet provides high-speed connectivity but lacks the inherent multi-tenant isolation and traffic engineering capabilities of MPLS VPN. DSL is a broadband technology suitable for small offices or residential environments but cannot provide enterprise-grade segmentation, QoS, or scalable virtualized connections.

MPLS VPNs also integrate with modern enterprise network designs that include hybrid cloud deployments. Enterprises can securely extend their on-premises network to cloud providers or colocation sites using MPLS VPNs, ensuring consistent security policies, predictable performance, and simplified management. Traffic engineering features allow optimization of bandwidth usage, reducing latency and congestion for critical applications such as VoIP, video conferencing, or ERP systems.

From an operational standpoint, MPLS VPNs reduce the complexity of managing multiple leased lines or private circuits, offering a more flexible and cost-effective solution. Service providers can dynamically provision VPNs, segment traffic for multiple customers, and maintain high availability through redundant MPLS paths. Enterprises benefit from SLA-backed performance, centralized control, and simplified troubleshooting through VRF-based monitoring and reporting tools.

In summary, MPLS VPNs provide virtual point-to-point or point-to-multipoint connections over a shared backbone, support multiple tenants with VRF-based isolation, and offer traffic engineering, QoS, and scalable routing. This makes option B correct.

Question 43:

Which Cisco feature allows seamless management of wireless clients, application visibility, and network assurance across enterprise networks?

A) Cisco ISE
B) Cisco DNA Center
C) Cisco Prime Infrastructure
D) NetFlow

Answer:

B) Cisco DNA Center

Explanation:

Cisco Digital Network Architecture (DNA) is a modern enterprise network architecture designed to provide automation, policy-driven management, and assurance. Cisco DNA Center is the centralized platform that enables seamless management of wired and wireless networks, delivering application visibility, client analytics, and policy enforcement across the enterprise.

DNA Center integrates network telemetry, automation, and machine learning to provide proactive monitoring and operational insights. For wireless clients, DNA Center collects detailed data about signal strength, connection quality, roaming behavior, and client experience. This information allows administrators to detect issues such as coverage gaps, interference, or capacity constraints and to take corrective actions before user experience is impacted.

Application visibility is a key feature of DNA Center. It can classify network traffic based on application type, user role, and device type, providing real-time monitoring and reporting. This allows IT teams to prioritize critical applications, enforce QoS policies, and troubleshoot performance issues more efficiently. By understanding application usage patterns, organizations can optimize bandwidth allocation and plan for capacity upgrades.

Assurance in DNA Center leverages artificial intelligence and machine learning to predict and prevent network problems. Continuous analytics detect anomalies, assess network health, and provide actionable recommendations. The platform can automatically adjust policies, allocate resources, or notify administrators about potential issues. This proactive approach reduces mean time to repair (MTTR) and improves overall service reliability.

Policy management in DNA Center is integrated with Cisco ISE for identity-based access control, allowing consistent enforcement across wired, wireless, and VPN connections. Intent-based networking enables administrators to define business intent policies, which are then translated into device-level configurations automatically, reducing configuration errors and operational overhead.

Other tools such as Cisco Prime Infrastructure provide network monitoring and management but lack the advanced automation, AI-driven assurance, and policy integration offered by DNA Center. ISE focuses on identity-based access and security enforcement, while NetFlow provides traffic visibility and analytics but does not manage policies or assure network health proactively.

In enterprise deployments, DNA Center enables a single-pane-of-glass view of the network, integrating wired, wireless, and SD-Access environments. It supports zero-touch provisioning, software image management, and network segmentation through security group tags (SGTs). These capabilities allow enterprises to scale rapidly, maintain consistent policies, and optimize network performance across multiple sites.

In conclusion, Cisco DNA Center provides centralized management, client visibility, application assurance, and policy enforcement, ensuring seamless operation and optimization of enterprise networks. This makes option B correct.

Question 44:

Which protocol is used to provide redundancy for default gateways in a LAN environment, supporting both Cisco-proprietary and open standard implementations?

A) HSRP
B) VRRP
C) GLBP
D) Both A and B

Answer:

D) Both A and B

Explanation:

In enterprise networks, default gateway redundancy is essential to maintain uninterrupted connectivity for hosts in case a router fails. Two widely used protocols that provide this functionality are HSRP (Hot Standby Router Protocol) and VRRP (Virtual Router Redundancy Protocol). Both protocols enable multiple routers to share a virtual IP address, which acts as the default gateway for devices on a subnet, ensuring continuous network availability.

HSRP is a Cisco-proprietary protocol. In an HSRP configuration, routers are assigned roles such as active and standby. The active router handles traffic for the virtual IP address, while the standby router monitors the active router’s status. If the active router fails, the standby router takes over, providing seamless failover. HSRP also supports multiple groups for load balancing, preemption to allow higher-priority routers to become active, and authentication to secure HSRP messages.

VRRP is an open standard protocol with similar functionality. VRRP elects a master router to handle traffic for the virtual IP, with backup routers available for failover. VRRP supports preemption, priority-based election, and advertisement intervals to monitor master router health. Being a standard protocol, VRRP allows interoperability across multi-vendor networks, unlike HSRP, which is limited to Cisco devices.

Both protocols rely on periodic hello or advertisement messages to detect router failures. When a failure is detected, the virtual IP is quickly assumed by another router, minimizing downtime. These protocols complement Layer 2 redundancy protocols such as STP, which prevent network loops but do not address gateway availability.

GLBP (Gateway Load Balancing Protocol) is another Cisco-proprietary protocol that provides both redundancy and load balancing across multiple gateways. While GLBP supports multiple active routers simultaneously, HSRP and VRRP focus primarily on failover.

Implementing HSRP or VRRP ensures high availability for critical applications, VoIP, and enterprise services. In multi-vendor environments, VRRP is preferred for interoperability, while HSRP is common in Cisco-dominant networks. For maximum resilience, these protocols are often combined with redundant Layer 2 links and path optimization strategies.

In summary, both HSRP and VRRP provide default gateway redundancy in LAN environments, offering failover capabilities and continuous availability. Therefore, option D is correct.

Question 45:

Which wireless standard supports MU-MIMO and operates primarily in the 5 GHz band for high-throughput enterprise deployments?

A) 802.11n
B) 802.11ac
C) 802.11a
D) 802.11b

Answer:

B) 802.11ac

Explanation:

802.11ac, also known as Wi-Fi 5, is a wireless standard designed for high-throughput enterprise deployments. Unlike previous standards such as 802.11n, 802.11ac operates primarily in the 5 GHz band, which provides more channels, reduced interference, and higher bandwidth capacity. One of its key enhancements is support for MU-MIMO (Multi-User Multiple Input Multiple Output), allowing multiple devices to communicate with an access point simultaneously, improving overall network efficiency and client performance.

The 5 GHz band offers more non-overlapping channels than the 2.4 GHz band, reducing co-channel interference and providing better performance in high-density environments such as enterprise campuses, stadiums, and offices. 802.11ac also supports channel widths up to 160 MHz, higher-order modulation schemes (256-QAM), and beamforming, all of which contribute to higher data rates and improved coverage.

MU-MIMO is a significant improvement over single-user MIMO (SU-MIMO) used in 802.11n. It allows the access point to transmit to multiple clients simultaneously rather than sequentially, reducing latency and enhancing throughput for high-density deployments. Beamforming directs the RF energy toward connected clients, improving signal quality and coverage, especially in challenging indoor environments.

Other wireless standards have limitations in throughput and efficiency. 802.11n operates in both 2.4 GHz and 5 GHz bands but lacks MU-MIMO and higher channel width support. 802.11a operates in 5 GHz but has lower throughput and fewer enhancements. 802.11b operates in 2.4 GHz and provides very low data rates unsuitable for modern enterprise needs.

In enterprise networks, 802.11ac supports high-bandwidth applications such as video conferencing, cloud services, large file transfers, and real-time collaboration. Its backward compatibility ensures older devices can still connect, while new devices benefit from the enhanced capabilities of MU-MIMO, wider channels, and higher modulation schemes. Integration with wireless controllers and network management platforms allows centralized policy enforcement, QoS, and client analytics for optimized network performance.

In summary, 802.11ac combines operation in the 5 GHz band, MU-MIMO support, and high-throughput features, making it the preferred choice for enterprise wireless deployments. Therefore, option B is correct.

Question 46:

Which routing protocol supports unequal-cost load balancing, fast convergence, and is Cisco-proprietary for IPv4 and IPv6 networks?

A) OSPF
B) EIGRP
C) RIP
D) BGP

Answer:

B) EIGRP

Explanation:

Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco-proprietary routing protocol that provides efficient, scalable, and fast-converging routing solutions for enterprise networks. One of its key advantages is support for unequal-cost load balancing, which allows traffic to be distributed across multiple routes with different metrics, improving network utilization without compromising loop-free routing. EIGRP uses the Diffusing Update Algorithm (DUAL) to guarantee loop-free operation and rapid convergence in response to network topology changes.

EIGRP maintains three primary tables: the neighbor table, the topology table, and the routing table. The neighbor table tracks directly connected EIGRP routers, while the topology table stores all routes learned from neighbors along with their metrics. The routing table contains the best routes selected based on feasibility conditions and metrics calculated by DUAL. By maintaining backup paths in the topology table, EIGRP can switch to an alternative route almost instantaneously if a primary path fails, ensuring minimal downtime.

EIGRP uses a composite metric based on bandwidth, delay, load, and reliability, which allows administrators to fine-tune routing decisions and prioritize critical traffic. Unequal-cost load balancing is implemented using the variance command, enabling traffic to be distributed across backup paths that meet the feasibility condition. This capability enhances bandwidth efficiency, particularly in enterprise networks with multiple redundant links.

Fast convergence is a hallmark of EIGRP. When a network change occurs, DUAL recalculates affected routes and immediately activates feasible backup routes. Unlike distance-vector protocols like RIP, which rely on periodic updates and are prone to loops, EIGRP sends partial updates only when changes occur, reducing network overhead and accelerating convergence.

EIGRP supports both IPv4 and IPv6 networks, making it versatile for modern dual-stack environments. It also integrates seamlessly with route summarization, authentication, and VLSM/CIDR networks, ensuring compatibility with hierarchical enterprise network designs.

Other protocols have limitations compared to EIGRP. OSPF, while scalable and widely deployed, only supports equal-cost load balancing and requires a hierarchical area-based design to scale effectively. RIP is limited by a maximum hop count and slow convergence, making it unsuitable for large networks. BGP is designed for inter-domain routing and does not inherently support fast convergence for internal enterprise networks.

In summary, EIGRP’s support for unequal-cost load balancing, rapid convergence, loop-free routing with DUAL, and dual-stack IPv4/IPv6 capability makes it the preferred Cisco-proprietary protocol for enterprise networks. Therefore, option B is correct.

Question 47:

Which technology enables the creation of overlay networks on top of an existing IP infrastructure to support multi-tenancy and network virtualization?

A) VLAN
B) VXLAN
C) MPLS
D) GRE

Answer:

B) VXLAN

Explanation:

Virtual Extensible LAN (VXLAN) is a modern network virtualization technology designed to address the limitations of traditional VLANs in large-scale, multi-tenant environments. VXLAN encapsulates Layer 2 Ethernet frames within Layer 3 IP packets, enabling Layer 2 networks to extend over a Layer 3 infrastructure. This overlay approach allows enterprises to deploy flexible and scalable network segments that are independent of the underlying physical network topology.

VXLAN uses a 24-bit VXLAN Network Identifier (VNI) to create up to 16 million unique logical networks, vastly exceeding the 4,096 VLAN limit. Each VNI represents a separate broadcast domain, isolating tenants or workloads in multi-tenant environments. Encapsulation ensures that traffic from one VXLAN segment is isolated from others, maintaining security and segmentation across the data center.

VXLAN can operate with control plane protocols like EVPN (Ethernet VPN), which provides MAC address learning, distribution, and loop prevention across VXLAN overlays. EVPN integration reduces the need for flooding unknown traffic, improves convergence, and allows dynamic workload mobility across multiple sites. This feature is particularly important in cloud-based data centers where virtual machines or containers may frequently move between hosts.

Other technologies provide limited solutions for similar challenges. VLANs offer basic segmentation but cannot scale effectively in multi-tenant or cloud environments. MPLS can transport traffic efficiently across wide-area networks but is primarily a Layer 3 technology and does not provide the large-scale Layer 2 overlay functionality that VXLAN offers. GRE is a tunneling protocol that encapsulates traffic but does not provide multi-tenant segmentation or scalable network virtualization features.

VXLAN also supports automation and orchestration, integrating with SDN controllers and Cisco DNA Center. These tools allow administrators to dynamically provision networks, apply policies, and ensure consistent security across the overlay. The overlay architecture also supports microsegmentation, enabling fine-grained security policies that follow workloads regardless of physical location.

Performance is a key consideration in VXLAN deployments. Hardware offloading in modern network interface cards (NICs) and switches ensures that encapsulation and decapsulation are handled efficiently, minimizing latency and maximizing throughput. VXLAN supports multicast, unicast, and head-end replication methods for handling broadcast, unknown unicast, and multicast (BUM) traffic, ensuring efficient and scalable operation.

In conclusion, VXLAN enables the creation of overlay networks on top of an existing IP infrastructure, providing scalable, isolated, and flexible network virtualization for multi-tenant enterprise environments. Therefore, option B is correct.

Question 48:

Which Cisco feature enables network segmentation, consistent policy enforcement, and security across both wired and wireless networks?

A) Cisco ISE
B) Cisco DNA Center
C) NetFlow
D) ACLs

Answer:

A) Cisco ISE

Explanation:

Cisco Identity Services Engine (ISE) is a comprehensive network security solution that enables identity-based access control, network segmentation, and policy enforcement across wired, wireless, and VPN networks. ISE integrates with AAA (Authentication, Authorization, and Accounting) protocols, 802.1X authentication, and centralized policy management to ensure that only authorized users and devices can access specific network resources.

ISE uses identity and context information to enforce security policies. Devices can be profiled based on type, operating system, and behavior. Users are authenticated through credentials, certificates, or tokens, and policies can be applied based on role, location, device compliance, or time of day. This enables segmentation of network traffic to reduce the attack surface and ensures that different types of devices or tenants receive appropriate levels of access.

Posture assessment is a critical feature of ISE, verifying that devices meet security compliance requirements before granting access. For example, corporate laptops may be allowed full network access, whereas guest devices or non-compliant endpoints may be restricted to a limited VLAN or captive portal. This protects enterprise resources while providing flexibility for legitimate users.

ISE also supports Security Group Tags (SGTs), which enable scalable policy enforcement across the network. SGTs allow administrators to apply security policies that follow users and devices, rather than being tied to a specific VLAN or physical segment. Integration with Cisco TrustSec ensures that access control policies are consistently applied across the enterprise, including both wired and wireless networks.

Other options provide partial solutions. Cisco DNA Center enables network automation and assurance but does not provide detailed identity-based access control. NetFlow provides visibility and analytics but does not enforce policies. ACLs enforce security rules on individual devices but lack centralized policy management and dynamic context-awareness.

ISE’s integration with identity providers, mobile device management (MDM), and endpoint compliance solutions ensures a cohesive and secure enterprise network. It is particularly useful in environments with BYOD, IoT devices, or multi-tenant networks, where consistent policy enforcement is critical for both security and operational efficiency.

In summary, Cisco ISE provides identity-based network segmentation, consistent policy enforcement, and security across wired and wireless networks, making option A correct.

Question 49:

Which WAN technology allows for traffic engineering, guaranteed QoS, and supports multiple tenants in enterprise networks?

A) MPLS
B) Frame Relay
C) DSL
D) Metro Ethernet

Answer:

A) MPLS

Explanation:

Multiprotocol Label Switching (MPLS) is a WAN technology widely used in enterprise networks to provide scalable, flexible, and high-performance connectivity. MPLS operates by forwarding packets based on labels rather than IP headers, enabling traffic engineering, guaranteed quality of service (QoS), and support for multiple tenants through virtual routing and forwarding (VRF) instances.

MPLS labels are attached to packets at ingress routers, which assign a label based on the destination and service requirements. Intermediate routers forward the packets using label-switching tables, avoiding complex IP header lookups at each hop. This enables faster packet forwarding, predictable latency, and deterministic paths through the network. Traffic engineering features allow network administrators to prioritize certain types of traffic, optimize bandwidth usage, and avoid congestion.

MPLS VPNs extend the benefits of MPLS to multi-tenant environments. Each tenant can have a dedicated VRF, isolating routing information and traffic from other tenants. This enables overlapping IP address spaces, customized routing policies, and centralized management of security and QoS. Layer 2 VPNs (VPLS) and Layer 3 VPNs provide additional flexibility for extending LANs or IP networks across WANs.

Other WAN technologies have limitations. Frame Relay is largely legacy and lacks modern QoS and scalability features. DSL is limited in bandwidth and is generally unsuitable for enterprise WAN requirements. Metro Ethernet offers high-speed connectivity but does not provide inherent traffic engineering or multi-tenant isolation features comparable to MPLS.

MPLS integrates with modern enterprise architectures, including hybrid cloud and SD-WAN deployments, enabling secure and predictable connectivity to remote sites and cloud services. Its ability to combine multiple service classes, guarantee SLAs, and isolate tenants makes it the preferred WAN technology for large enterprises.

In summary, MPLS allows traffic engineering, guaranteed QoS, and supports multiple tenants using VRFs, making it the correct choice, option A.

Question 50:

Which wireless security standard is considered the enterprise standard for secure Wi-Fi with centralized authentication?

A) WEP
B) WPA2-Enterprise
C) WPA-PSK
D) TKIP

Answer:

B) WPA2-Enterprise

Explanation:

WPA2-Enterprise is the industry-standard wireless security protocol for enterprise networks, providing strong encryption, centralized authentication, and role-based access control. Unlike personal Wi-Fi security methods such as WPA-PSK, which rely on shared passwords, WPA2-Enterprise uses IEEE 802.1X authentication in combination with RADIUS servers to verify user and device credentials before granting network access.

WPA2-Enterprise uses AES (Advanced Encryption Standard) with CCMP for strong encryption and integrity protection, ensuring confidentiality of wireless communications. It supports mutual authentication, ensuring that both clients and access points can verify each other, protecting against man-in-the-middle attacks. Authentication can be based on certificates, usernames/passwords, or tokens, providing flexibility for enterprise deployments.

This protocol is critical in environments where multiple users and devices connect simultaneously, as it allows centralized management of credentials, policies, and network access. Integration with Cisco ISE enables dynamic VLAN assignment, device profiling, posture assessment, and consistent policy enforcement across wired and wireless networks.

Other options such as WEP and TKIP are outdated and vulnerable, offering minimal security protection. WPA-PSK is suitable for home or small office networks but lacks centralized authentication and granular access control required for enterprise environments. WPA2-Enterprise ensures that user credentials are validated individually, reducing the risk of unauthorized access and providing a scalable, secure solution for enterprise Wi-Fi.

In summary, WPA2-Enterprise offers robust encryption, centralized authentication, and policy-based access control, making it the preferred security standard for enterprise wireless networks. Therefore, option B is correct.

Question 51:

Which Cisco technology allows centralized policy-based automation and network assurance for enterprise LAN and WLAN environments?

A) Cisco ISE
B) Cisco DNA Center
C) NetFlow
D) Prime Infrastructure

Answer:

B) Cisco DNA Center

Explanation:

Cisco DNA Center is the cornerstone of Cisco’s Digital Network Architecture (DNA) and is designed to provide centralized management, policy automation, and assurance for enterprise LAN and WLAN networks. It acts as a single-pane-of-glass platform where network administrators can define business intent, deploy policies, automate configurations, and monitor network performance proactively.

One of the primary features of Cisco DNA Center is policy-based automation. Administrators can create intent-based policies that define how devices, users, and applications should be treated on the network. These policies are then automatically translated into device-level configurations across routers, switches, and wireless access points. For example, a policy can specify that IoT devices receive limited bandwidth and are placed in a separate VLAN, while corporate laptops receive full access to enterprise resources. Automation reduces human error, accelerates deployment, and ensures consistent policy enforcement across the network.

Another key function is network assurance. Cisco DNA Center continuously collects telemetry from network devices, clients, and applications, using technologies like Streaming Telemetry and Cisco’s Assurance Analytics Engine. This telemetry is analyzed using AI and machine learning to identify anomalies, performance bottlenecks, and potential faults before they affect users. For instance, if wireless clients experience high packet loss or interference, DNA Center can detect these issues, suggest remediation, or even trigger automated corrective actions.

Cisco DNA Center also integrates with Cisco ISE to enforce identity-based policies, allowing role-based access and device profiling to secure the network dynamically. By combining automation and assurance, DNA Center enables predictive troubleshooting, reduces mean time to repair (MTTR), and ensures a high-quality user experience across both wired and wireless networks.

Compared to other tools, Cisco ISE focuses on identity-based access control, NetFlow provides traffic monitoring and analytics, and Prime Infrastructure primarily manages devices. While each of these tools is important, Cisco DNA Center uniquely integrates automation, policy management, and assurance into a single platform. This integration is essential for modern enterprise networks that require agility, security, and consistent policy enforcement at scale.

In conclusion, Cisco DNA Center provides centralized, intent-based automation and network assurance for LAN and WLAN environments, enabling enterprises to optimize operations, enforce policies consistently, and proactively detect and resolve network issues. Therefore, option B is correct.

Question 52:

Which protocol is used in data center networks to distribute MAC address information across VXLAN overlays for seamless Layer 2 connectivity?

A) OSPF
B) BGP EVPN
C) STP
D) RSTP

Answer:

B) BGP EVPN

Explanation:

In modern data center networks, Virtual Extensible LAN (VXLAN) is widely deployed to provide scalable Layer 2 overlay networks over a Layer 3 IP infrastructure. However, to maintain seamless Layer 2 connectivity across multiple VXLAN segments, MAC address learning and distribution are essential. BGP EVPN (Border Gateway Protocol Ethernet VPN) is the protocol used for this purpose, providing control-plane-based MAC address distribution for VXLAN overlays.

BGP EVPN operates by creating a distributed control plane where VXLAN Tunnel Endpoints (VTEPs) exchange MAC address reachability information using BGP. Each VTEP advertises the MAC addresses associated with its local endpoints along with the corresponding VNI (VXLAN Network Identifier) and IP address. This allows remote VTEPs to learn the MAC addresses of endpoints in different VXLAN segments without relying on traditional flooding mechanisms. By using a control plane, BGP EVPN significantly reduces broadcast, unknown unicast, and multicast (BUM) traffic, improving network efficiency and scalability.

In addition to MAC distribution, BGP EVPN supports advanced features such as active-active multi-homing, loop prevention, and integrated routing with Layer 3 VXLAN gateways. Active-active multi-homing allows multiple VTEPs to forward traffic for the same VXLAN segment, providing redundancy and load balancing. Loop prevention mechanisms rely on the BGP control plane to enforce a deterministic path for traffic, eliminating the reliance on spanning tree protocols and reducing convergence times in large data center networks.

Other protocols listed, such as OSPF, STP, and RSTP, serve different purposes. OSPF is a Layer 3 routing protocol used for IP networks, not MAC address distribution. STP and RSTP are Layer 2 protocols designed to prevent loops in Ethernet networks but do not provide scalable MAC address distribution for overlays. Without BGP EVPN, VXLAN overlays would have to rely on flooding for MAC learning, which does not scale well in large multi-tenant data centers.

BGP EVPN also integrates with other enterprise and data center technologies such as software-defined networking (SDN), Cisco ACI, and network virtualization solutions. This integration allows dynamic provisioning of VXLAN overlays, automated endpoint registration, and policy enforcement across the data center. Additionally, BGP EVPN provides support for redundancy and failover by advertising multiple paths, ensuring uninterrupted connectivity even during hardware or link failures.

In summary, BGP EVPN is the protocol that enables control-plane-based MAC address distribution across VXLAN overlays, providing scalable, efficient, and seamless Layer 2 connectivity in modern data center networks. Therefore, option B is correct.

Question 53:

Which feature of OSPF improves convergence time and reduces flooding in large enterprise networks by grouping routers into areas?

A) Stub areas
B) Route summarization
C) Hierarchical design
D) SPF algorithm

Answer:

C) Hierarchical design

Explanation:

Open Shortest Path First (OSPF) is a link-state routing protocol commonly deployed in enterprise networks for its scalability, fast convergence, and deterministic routing. One of the critical features that enable OSPF to scale in large networks is its hierarchical design, which divides the network into multiple areas. This hierarchical structure reduces the size of the link-state database (LSDB), limits flooding, and accelerates convergence.

In a hierarchical OSPF design, Area 0 acts as the backbone, connecting all other areas. This backbone ensures a consistent path for inter-area traffic. Each non-backbone area contains a subset of routers and networks, maintaining its own LSDB for intra-area routes. By restricting the scope of LSAs (Link-State Advertisements) within an area, OSPF reduces the volume of updates that need to be processed by all routers, minimizing CPU utilization and memory requirements.

Route summarization at area boundaries further enhances scalability. OSPF can aggregate multiple networks into a single summarized route when advertising to other areas. This reduces the size of routing tables and prevents unnecessary flooding of detailed route information across the entire OSPF domain.

Other features, such as stub areas and the SPF (Shortest Path First) algorithm, also contribute to OSPF operation but do not provide the same level of scalability as hierarchical design. Stub areas limit external routes and reduce LSA types within a specific area, while the SPF algorithm calculates shortest paths based on the LSDB. Both improve efficiency but are subordinate to the benefits gained from hierarchical segmentation.

In enterprise networks, hierarchical OSPF design allows predictable and stable operation. It improves convergence times because LSAs are contained within an area, limiting the number of routers that must recalculate SPF trees after topology changes. It also facilitates network planning, troubleshooting, and capacity management by organizing the network into logical segments.

The hierarchical approach also enables large-scale designs that can support thousands of routers and complex topologies without overwhelming routers with LSAs. It provides flexibility for network growth, redundancy, and segmentation while maintaining fast convergence and loop-free routing.

In summary, OSPF’s hierarchical design improves convergence and reduces flooding by grouping routers into areas, enabling large enterprise networks to scale efficiently. Therefore, option C is correct.

Question 54:

Which WAN technology provides a secure, high-performance virtual network that isolates multiple tenants and supports QoS?

A) MPLS VPN
B) Frame Relay
C) Metro Ethernet
D) DSL

Answer:

A) MPLS VPN

Explanation:

Multiprotocol Label Switching Virtual Private Networks (MPLS VPNs) are widely used in enterprise WAN environments to provide secure, high-performance connectivity while isolating multiple tenants. MPLS VPNs use labels to forward packets efficiently and provide separation of traffic for different tenants through Virtual Routing and Forwarding (VRF) instances.

MPLS VPNs can be deployed as Layer 2 VPNs or Layer 3 VPNs. Layer 2 VPNs extend Ethernet segments across the MPLS backbone, while Layer 3 VPNs provide IP-based routing separation. Each VRF maintains an independent routing table, allowing overlapping IP addresses across tenants without conflicts. This ensures complete traffic isolation, making MPLS VPN ideal for multi-tenant enterprise environments, managed services, and hybrid cloud connectivity.

Traffic engineering is a key feature of MPLS. By controlling label-switched paths (LSPs), network administrators can ensure certain traffic flows through predetermined routes, guaranteeing low latency and high performance for critical applications. Quality of Service (QoS) mechanisms in MPLS allow prioritization of voice, video, or other latency-sensitive traffic, ensuring reliable service delivery across the WAN.

Compared to other WAN technologies, MPLS VPNs provide several advantages. Frame Relay is an outdated technology with limited scalability and QoS support. Metro Ethernet provides high-speed connectivity but lacks built-in multi-tenant isolation and traffic engineering. DSL offers low-speed access suitable for small offices but cannot provide enterprise-grade segmentation or performance guarantees.

MPLS VPNs are also compatible with hybrid cloud and SD-WAN architectures, allowing enterprises to extend secure connectivity to remote sites or cloud services without compromising isolation or performance. The ability to dynamically provision VRFs, apply QoS, and integrate with network monitoring tools simplifies management and improves reliability.

In conclusion, MPLS VPNs provide secure, high-performance virtual networks with tenant isolation and QoS support, making them the preferred choice for enterprise WAN environments. Therefore, option A is correct.

Question 55:

Which wireless standard operates primarily in the 5 GHz band, supports MU-MIMO, and is suitable for high-density enterprise deployments?

A) 802.11n
B) 802.11ac
C) 802.11a
D) 802.11b

Answer:

B) 802.11ac

Explanation:

802.11ac, also known as Wi-Fi 5, is a high-throughput wireless standard that operates primarily in the 5 GHz band. It introduces several enhancements over previous standards to support high-density enterprise environments, including Multi-User MIMO (MU-MIMO), wider channel widths (up to 160 MHz), beamforming, and higher-order modulation (256-QAM).

MU-MIMO allows multiple clients to communicate with the access point simultaneously, improving network efficiency and throughput in environments where many devices are connected, such as offices, campuses, and stadiums. Beamforming focuses the RF energy toward the client device, enhancing signal quality, coverage, and performance. The 5 GHz band provides more non-overlapping channels than 2.4 GHz, reducing interference and co-channel contention.

Other standards have limitations. 802.11n supports MIMO but not MU-MIMO, operates in both 2.4 GHz and 5 GHz bands, and provides lower maximum throughput. 802.11a operates in 5 GHz but lacks the advanced enhancements and high throughput of 802.11ac. 802.11b operates in 2.4 GHz and is outdated, offering very low data rates unsuitable for modern enterprise applications.

In enterprise deployments, 802.11ac enables high-throughput applications such as video conferencing, VoIP, cloud services, and large file transfers. It integrates with wireless controllers for centralized management, policy enforcement, and analytics, ensuring consistent performance across the network. Its enhancements make it the standard for enterprise wireless networks requiring high capacity, low latency, and efficient spectrum utilization.

In summary, 802.11ac operates in the 5 GHz band, supports MU-MIMO, and is optimized for high-density enterprise environments. Therefore, option B is correct.

Question 56:

Which feature of EIGRP ensures loop-free paths and enables fast convergence by maintaining backup routes?

A) DUAL algorithm
B) Split horizon
C) Hold timer
D) Route poisoning

Answer:

A) DUAL algorithm

Explanation:

Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco-proprietary routing protocol designed to provide fast convergence, loop-free routing, and scalable enterprise network support. The core mechanism that ensures EIGRP achieves these goals is the Diffusing Update Algorithm (DUAL). DUAL allows EIGRP to calculate the shortest path to each destination while simultaneously maintaining feasible backup routes that can be activated instantly if the primary route fails.

EIGRP maintains three primary data structures: the neighbor table, topology table, and routing table. The neighbor table stores information about directly connected EIGRP routers. The topology table contains all learned routes, including feasible distance (FD) and reported distance (RD). The routing table contains the best paths selected by DUAL. By analyzing these distances, DUAL identifies loop-free routes and ensures that only feasible paths are used to forward traffic.

The feasibility condition is a critical component of DUAL. It states that a route is feasible if its reported distance from a neighbor is less than the feasible distance of the current best path. Routes that meet this condition are considered loop-free and can be installed as backup routes. This ensures that when a primary path fails, the router can immediately switch to a backup without recalculating the entire topology, minimizing downtime and improving network reliability.

DUAL also supports unequal-cost load balancing. By using the variance command, traffic can be distributed across multiple feasible paths with different metrics, optimizing bandwidth utilization while maintaining loop-free operation. This is particularly important in enterprise networks with redundant links or complex topologies.

Other EIGRP features such as split horizon, hold timers, and route poisoning contribute to stability and loop prevention but do not provide the same comprehensive loop-free convergence mechanism as DUAL. Split horizon prevents updates from being sent back out the interface from which they were received. Hold timers monitor neighbor connectivity. Route poisoning advertises unreachable routes to ensure consistency across the network. However, DUAL uniquely combines loop prevention, backup path maintenance, and fast convergence in a single algorithm.

DUAL also allows EIGRP to scale efficiently in large networks. By maintaining backup routes and reducing unnecessary recalculations, DUAL reduces CPU and memory utilization on routers. This makes it suitable for enterprise networks with hundreds or thousands of routers, redundant paths, and high availability requirements.

From a design perspective, DUAL provides predictable routing behavior. Network engineers can plan redundant paths and confidently rely on EIGRP to maintain loop-free connectivity. The fast convergence properties of DUAL are critical for real-time applications such as VoIP, video conferencing, and data replication, where network outages or delays can severely impact performance.

In summary, the DUAL algorithm is the fundamental feature that enables EIGRP to maintain loop-free paths, support fast convergence, and provide feasible backup routes for reliable enterprise network operation. Therefore, option A is correct.

Question 57:

Which protocol allows consistent identity-based access policies for wired, wireless, and VPN connections in an enterprise network?

A) RADIUS
B) TACACS+
C) Cisco ISE
D) LDAP

Answer:

C) Cisco ISE

Explanation:

Cisco Identity Services Engine (ISE) is a centralized policy management and access control solution for enterprise networks. It enables consistent identity-based access policies across wired, wireless, and VPN connections. By integrating authentication, authorization, and accounting (AAA) services with device profiling, posture assessment, and policy enforcement, ISE ensures that users and devices are granted access according to defined roles, compliance status, and network context.

In enterprise networks, the diversity of devices and user types presents a significant security challenge. Employees, contractors, guests, and IoT devices all require varying levels of access to network resources. Cisco ISE addresses this challenge by centralizing policy decisions based on identity, device type, role, location, and posture. For wired networks, ISE leverages 802.1X authentication at the port level to ensure only authorized devices can connect. For wireless networks, it supports WPA2/WPA3 Enterprise authentication to enforce consistent policies across all wireless access points. For VPN connections, ISE verifies identity and device compliance before granting access to internal resources.

One of the key features of ISE is device profiling. ISE can automatically identify devices connecting to the network, categorize them by type, manufacturer, and operating system, and apply appropriate access policies. Posture assessment ensures devices meet security compliance requirements such as updated antivirus, OS patches, or configuration standards before access is granted. Non-compliant devices can be placed in quarantine VLANs or redirected to remediation portals, reducing risk from compromised endpoints.

Security Group Tags (SGTs) further enhance ISE functionality. SGTs allow policy enforcement to follow users and devices across the network, independent of physical location or VLAN. This enables consistent segmentation and access control across the enterprise, simplifying policy management in multi-site deployments. Integration with Cisco TrustSec ensures that policies are consistently applied across all network segments.

While RADIUS, TACACS+, and LDAP are relevant technologies in network authentication and authorization, they do not provide the same centralized, context-aware policy enforcement as ISE. RADIUS provides AAA services but lacks advanced profiling, posture assessment, and centralized policy management. TACACS+ is primarily used for device administration access. LDAP is a directory service for authentication but does not enforce granular network access policies.

ISE also supports integration with mobile device management (MDM) solutions and third-party security products, enabling a holistic approach to network security. By providing visibility into who and what is on the network, administrators can make informed decisions, enforce compliance, and respond quickly to threats.

In enterprise deployments, Cisco ISE provides seamless and consistent access policies across wired, wireless, and VPN connections, ensuring secure, scalable, and manageable network access. Therefore, option C is correct.

Question 58:

Which data center technology encapsulates Layer 2 Ethernet frames within Layer 3 IP packets to extend networks across large-scale environments?

A) VLAN
B) VXLAN
C) GRE
D) MPLS

Answer:

B) VXLAN

Explanation:

Virtual Extensible LAN (VXLAN) is a network virtualization technology widely used in modern data centers to extend Layer 2 networks over Layer 3 infrastructure. It addresses limitations of traditional VLANs, such as the 4,096 VLAN ID restriction, by providing a 24-bit VXLAN Network Identifier (VNI), enabling up to 16 million unique logical networks. VXLAN encapsulates Layer 2 Ethernet frames into UDP-encapsulated IP packets, creating overlay networks that can span across data centers and support multi-tenant environments.

VXLAN uses VXLAN Tunnel Endpoints (VTEPs) to perform encapsulation and decapsulation of Ethernet frames. Each VTEP maps a VNI to a specific broadcast domain and handles traffic forwarding across the underlying IP network. This overlay architecture allows for flexible deployment of virtual networks that are decoupled from the physical topology, supporting dynamic workloads, VM mobility, and seamless multi-tenant isolation.

Integration with BGP EVPN provides a control plane for MAC address distribution and loop prevention. Instead of relying on traditional flooding for MAC learning, BGP EVPN allows VTEPs to advertise endpoint MAC addresses, VNI mappings, and associated IP addresses to other VTEPs. This reduces broadcast traffic, improves convergence, and enables scalable Layer 2 extension across large data centers.

Other technologies have limitations for similar use cases. VLANs are restricted by the maximum number of IDs and do not scale well for multi-tenant overlays. GRE tunnels provide encapsulation but lack the control plane intelligence, multi-tenant segmentation, and scalability of VXLAN. MPLS is primarily a Layer 3 transport mechanism and does not provide native Layer 2 overlays or VXLAN-specific tenant isolation.

VXLAN also supports automation and orchestration, integrating with SDN controllers such as Cisco ACI or DNA Center. Administrators can dynamically provision overlays, enforce network policies, and monitor traffic at scale. Hardware offloading ensures encapsulation and decapsulation are handled efficiently, minimizing latency and maximizing throughput in high-performance data center networks.

In addition, VXLAN overlays enable microsegmentation, allowing granular security policies to follow workloads regardless of physical location. This enhances compliance and reduces the attack surface by segmenting traffic based on tenant, application, or role.

In summary, VXLAN encapsulates Layer 2 Ethernet frames within Layer 3 IP packets, providing scalable, multi-tenant Layer 2 extension over IP networks in modern data centers. Therefore, option B is correct.

Question 59:

Which wireless security protocol is considered the enterprise standard for strong encryption and centralized authentication?

A) WEP
B) WPA2-Enterprise
C) WPA-PSK
D) TKIP

Answer:

B) WPA2-Enterprise

Explanation:

WPA2-Enterprise is the industry-standard wireless security protocol for enterprise networks. It provides strong encryption using AES-CCMP and supports centralized authentication via IEEE 802.1X and RADIUS servers. Unlike WPA-PSK or WEP, which rely on shared secrets or weak encryption, WPA2-Enterprise authenticates each user or device individually, enabling scalable and secure access for large enterprises.

Centralized authentication ensures that users are verified before they gain network access. WPA2-Enterprise can use credentials, certificates, or tokens for authentication, allowing network administrators to enforce role-based access policies. Integration with Cisco ISE enhances functionality by enabling dynamic VLAN assignment, device profiling, and posture assessment. Devices that do not meet security standards can be restricted or quarantined, ensuring that the network remains secure even in BYOD or guest environments.

AES encryption ensures that wireless data is protected from eavesdropping and tampering. CCMP (Counter Mode with Cipher Block Chaining Message Authentication Code Protocol) provides strong data confidentiality, integrity, and authentication, which are essential for enterprise networks handling sensitive information.

Other protocols such as WEP and TKIP are outdated and vulnerable to attacks. WEP’s RC4 encryption is easily cracked, while TKIP is susceptible to known vulnerabilities. WPA-PSK is suitable for small networks but lacks centralized authentication and does not scale well for enterprise environments.

WPA2-Enterprise also supports seamless roaming between access points without requiring re-authentication for every handoff. This is critical in high-density environments such as campuses, offices, or warehouses where mobile clients move frequently. By providing strong encryption, centralized authentication, and dynamic policy enforcement, WPA2-Enterprise ensures secure, reliable, and scalable wireless connectivity for enterprise networks.

In conclusion, WPA2-Enterprise is the enterprise standard for secure Wi-Fi networks, providing AES encryption, centralized authentication, and policy enforcement, making option B correct.

Question 60:

Which WAN technology supports traffic engineering, multiple tenants, and predictable QoS for enterprise networks?

A) MPLS
B) Frame Relay
C) Metro Ethernet
D) DSL

Answer:

A) MPLS

Explanation:

Multiprotocol Label Switching (MPLS) is a WAN technology widely used in enterprise networks to provide scalable, predictable, and multi-tenant connectivity. MPLS forwards packets based on labels rather than IP headers, enabling efficient routing, traffic engineering, and quality of service (QoS) guarantees. This makes it particularly suitable for enterprises that require reliable connectivity between branch offices, data centers, and cloud services.

MPLS VPNs use Virtual Routing and Forwarding (VRF) instances to isolate traffic for multiple tenants or business units. Each VRF maintains its own routing table, allowing overlapping IP address spaces and ensuring complete separation of traffic. MPLS labels are applied at the ingress router, and intermediate routers forward packets using the label-switching table. This mechanism reduces routing table lookup complexity and improves packet forwarding speed.

Traffic engineering allows administrators to define explicit paths for specific types of traffic, ensuring low latency and avoiding congested links. QoS mechanisms in MPLS can prioritize voice, video, or other latency-sensitive applications, providing predictable performance for critical enterprise services.

Other WAN technologies have limitations. Frame Relay is largely legacy and does not provide modern QoS or multi-tenant isolation. Metro Ethernet offers high-speed connectivity but lacks the traffic engineering and multi-tenant VPN capabilities inherent in MPLS. DSL is limited in bandwidth and is unsuitable for enterprise-grade applications.

MPLS integrates with hybrid cloud architectures, enabling secure connectivity to remote sites or cloud providers while maintaining tenant isolation and performance guarantees. It allows enterprises to centralize policy management, monitor traffic, and dynamically provision new connections without compromising security or QoS.

In summary, MPLS provides scalable, multi-tenant WAN connectivity with traffic engineering and predictable QoS, making it the preferred choice for enterprise networks. Therefore, option A is correct.